Quantitative trait locus mapping of root exudate metabolome in a Solanum lycopersicum Moneymaker x S. pimpinellifolium RIL population and their putative links to rhizosphere microbiome
Authors: Kim, B., Kramer, G., Leite, M. F. A., Snoek, B. L., Zancarini, A., Bouwmeester, H.
The study used untargeted metabolomics and QTL mapping in a tomato recombinant inbred line population to characterize root exudate composition and identify genetic loci controlling specific metabolites. It reveals domestication-driven changes in exudate profiles and links metabolic QTLs with previously reported microbial QTLs, suggesting a genetic basis for shaping the root microbiome.
The authors used a bottom‑up thermodynamic modelling framework to investigate how plants decode calcium signals, starting from Ca2+ binding to EF‑hand proteins and extending to higher‑order decoding modules. They identified six universal Ca2+-decoding modules that can explain variations in calcium sensitivity among kinases and provide a theoretical basis for interpreting calcium signal amplitude and frequency in plant cells.
Four barley genotypes were examined under simultaneous Fusarium culmorum infection and drought, revealing genotype-dependent Fusarium Head Blight severity and largely additive transcriptomic responses dominated by drought. Co‑expression and hormone profiling linked ABA and auxin to stress‑specific gene modules, and a multiple linear regression model accurately predicted combined‑stress gene expression from single‑stress data, suggesting modular regulation.
The study examined nitrogen use strategies in the model alga Chlamydomonas reinhardtii by comparing growth on ammonium, nitrate, and urea, finding similar molar nitrogen utilization efficiency under saturating conditions. Rapid nitrogen uptake and storage were demonstrated through pulse experiments, and source‑specific transcriptome analysis revealed distinct regulation of assimilation pathways and transporters, supporting a model of flexible nitrogen acquisition and storage.
The study investigates how maternal environmental conditions, specifically temperature and light intensity, influence seed longevity in eight Arabidopsis thaliana natural accessions. Seeds developed under higher temperature (27 °C) and high light showed increased longevity, with transcriptome analysis of the Bor-4 accession revealing dynamic changes in stored mRNAs, including upregulation of antioxidant defenses and raffinose family oligosaccharides. These findings highlight the genotype‑dependent modulation of seed traits by the maternal environment.
The study investigates the evolutionary shift from archegonial to embryo‑sac reproduction by analyzing transcriptomes of Ginkgo reproductive organs and related species. It reveals that the angiosperm pollen‑tube guidance module MYB98‑CRP‑ECS is active in mature Ginkgo archegonia and that, while egg cell transcription is conserved, changes in the fate of other female gametophyte cells drove the transition, providing a molecular framework for this major reproductive evolution.
A nested association mapping (NAM) population was created in lentil by crossing the cultivar CDC Redberry with 32 diverse genotypes, producing recombinant inbred lines that were field‑phenotyped for days to emergence, flowering, and maturity. Exome capture sequencing and genome‑wide association studies identified 14 significant loci, including both known and novel candidates, demonstrating the NAM design’s ability to uncover minor‑effect loci for complex traits. This publicly available lentil NAM population provides a high‑resolution resource for trait discovery and pre‑breeding.
Transcriptomic analysis of genotypes derived from Rosa wichurana unveils molecular mechanisms associated with quantitative resistance to Diplocarpon rosae
The study investigated the molecular basis of quantitative resistance to black spot disease in a Rosa wichurana × Rosa chinensis F1 population, identifying two major QTLs (B3 on LG3 and B5 on LG5). RNA‑seq of inoculated and control leaf samples at 0, 3, and 5 days post‑inoculation revealed extensive transcriptional reprogramming, with QTL B3 triggering classic defense pathways and QTL B5 showing a limited, distinct response. These findings highlight complex, QTL‑specific regulation underlying durable black‑spot resistance in roses.
The study applied a novel Stomatal Patterning Phenotype (SPP) spatial analysis to high‑throughput phenotyping data from 180 maize recombinant inbred lines, dissecting stomatal density into component traits related to cell size, packing, and positional probabilities. Using these derived traits, the authors built a structural equation model that explained 74% of stomatal density variation and identified specific quantitative trait loci for lateral and longitudinal stomatal patterning.
A comparative physiological study of persimmon cultivars with flat (Hiratanenashi) and round (Koushimaru) fruit shapes revealed that differences in cell proliferation, cell shape, and size contribute to shape variation. Principal component analysis of elliptic Fourier descriptors tracked shape changes, while histology and transcriptome profiling identified candidate genes, including a WOX13 homeobox gene, potentially governing fruit shape development.